DecisionControllerImpl.java

/*
 * Copyright 2012 International Business Machines Corp.
 * 
 * See the NOTICE file distributed with this work for additional information
 * regarding copyright ownership. Licensed under the Apache License, 
 * Version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.ibm.jbatch.container.impl;

import java.util.List;
import java.util.logging.Logger;

import javax.batch.runtime.StepExecution;

import com.ibm.jbatch.container.IExecutionElementController;
import com.ibm.jbatch.container.artifact.proxy.DeciderProxy;
import com.ibm.jbatch.container.artifact.proxy.InjectionReferences;
import com.ibm.jbatch.container.artifact.proxy.ProxyFactory;
import com.ibm.jbatch.container.exception.BatchContainerRuntimeException;
import com.ibm.jbatch.container.exception.BatchContainerServiceException;
import com.ibm.jbatch.container.jobinstance.RuntimeJobExecution;
import com.ibm.jbatch.container.jsl.ExecutionElement;
import com.ibm.jbatch.container.services.IPersistenceManagerService;
import com.ibm.jbatch.container.servicesmanager.ServicesManagerImpl;
import com.ibm.jbatch.container.status.ExecutionStatus;
import com.ibm.jbatch.container.status.ExtendedBatchStatus;
import com.ibm.jbatch.container.validation.ArtifactValidationException;
import com.ibm.jbatch.jsl.model.Decision;
import com.ibm.jbatch.jsl.model.Property;

public class DecisionControllerImpl implements IExecutionElementController {

	private final static String sourceClass = SplitControllerImpl.class.getName();
	private final static Logger logger = Logger.getLogger(sourceClass);

	private RuntimeJobExecution jobExecution; 

	private Decision decision;

	private StepExecution[] previousStepExecutions = null;

	private IPersistenceManagerService persistenceService = null;

	public DecisionControllerImpl(RuntimeJobExecution jobExecution, Decision decision) {
		this.jobExecution = jobExecution;
		this.decision = decision;
		persistenceService = ServicesManagerImpl.getInstance().getPersistenceManagerService();
	}

	@Override
	public ExecutionStatus execute() {

		String deciderId = decision.getRef();
		List<Property> propList = (decision.getProperties() == null) ? null : decision.getProperties().getPropertyList();

		DeciderProxy deciderProxy;

		//Create a decider proxy and inject the associated properties

		/* Set the contexts associated with this scope */
		//job context is always in scope
		//the parent controller will only pass one valid context to a decision controller
		//so two of these contexts will always be null
		InjectionReferences injectionRef = new InjectionReferences(jobExecution.getJobContext(), null, propList);

		try {
			deciderProxy = ProxyFactory.createDeciderProxy(deciderId,injectionRef );
		} catch (ArtifactValidationException e) {
			throw new BatchContainerServiceException("Cannot create the decider [" + deciderId + "]", e);
		}

		String exitStatus = deciderProxy.decide(this.previousStepExecutions);

		logger.fine("Decider exiting and setting job-level exit status to " + exitStatus);

		//Set the value returned from the decider as the job context exit status.
		this.jobExecution.getJobContext().setExitStatus(exitStatus);

		return new ExecutionStatus(ExtendedBatchStatus.NORMAL_COMPLETION, exitStatus);
	}

	protected void setPreviousStepExecutions(ExecutionElement previousExecutionElement, IExecutionElementController previousElementController) { 
		if (previousExecutionElement == null) {
			// only job context is available to the decider 
		} else if (previousExecutionElement instanceof Decision) {
			
			throw new BatchContainerRuntimeException("A decision cannot precede another decision.");
			
		}
		
		List<Long> previousStepExecsIds = previousElementController.getLastRunStepExecutions();
		
		StepExecution[] stepExecArray = new StepExecution[previousStepExecsIds.size()];
		
		for (int i=0; i < stepExecArray.length; i++) {
		    StepExecution stepExec = persistenceService.getStepExecutionByStepExecutionId(previousStepExecsIds.get(i));
		    stepExecArray[i] = stepExec;
		}

		this.previousStepExecutions =  stepExecArray;
		
	}


	@Override
	public void stop() { 
		// no-op
	}

    @Override
    public List<Long> getLastRunStepExecutions() {
        // TODO Auto-generated method stub
        return null;
    }


}